Center screw in distributors comes loose. done this with 3 different units. on 1994 Nissan Sentra

center screw in distributor comes loose. done this with 3 different units. Does anyone know why, and how to permanately fix it?

Asked by for the 1994 Nissan Sentra
1 answer 1 comment
I would make sure to tighten it to the proper torque but before that, put a drop if lock-tight on the screw.
A+ Japanese Auto Repair, San Carlos CA 94070
Loctite (green!) has been used! It must be retightened about every 2 weeks!